Antistatic photographic film



, of manufactured film through the camera.

3,264,100 ANTHS'ITATHC PHUTUGRAH'HHC FlLlt i E. Scudder Maclrey andAaron Ben-Ezra, lilinghamton,

N.Y., and Fred E. Woodward, Watchung, NJ, assignors to General Anilinedz Film @orporation, New York, N.Y., a corporation of Delaware NoDrawing. Filled Mar. 19, 1963, Ser. No. 266,175 4 Claims. (Cl. %-tl)This invention relates to photographic film and more particularly tofilm having anti-static coatings.

Considerable difficulty has been encountered in the manufacture and useof photographic film due to the accumulation of electrical charges onthe film. These elec trical charges, which are known as static, developwhen photographic film is handled during processing as, for example,when film sheets are separated from each other or when motion picturefilm is passed through a projector. The more serious difficulty is theaccumulation of static in the application of the various coatings in themanufacturing process of the photographic film and in the passageManifestations of these charges are glow discharges which afterdevelopment of the exposed film show up as black streaks or lines, or asirregular fogged patterns in the emulsion layer. Attempts have been madeto overcome static in films by the application of substances which areelectrolytes or possess hygroscopic properties. The function of thesesubstances is to impart conductivity to the film and thus dissipate theelectrical charges before their accumulation leads to local discharges.Many of these substances are incompatible with the materials which 'formone or more layers of the photographic film and introduce newmanufacturing difficulties.

It is an object of the present invention to provide a means foreliminating static charges on a photographic film.

It is a further object to provide a means for coating photographic filmwhereby the composition resulting therefrom has a reduced statictendency.

Other objects will be apparent from the following description:

The above and other objects of the invention are accomplished by thepresent invention by incorporating in layers of the film, or on eithersurface of the film, an inorganic or organic salt of a phosphate esterhaving the formula:

wherein R represents hydrogen or an alkyl group containing from 4 to 27carbon atoms, e.g., butyl, hexyl, octyl, nonyl, decyl, hendecyl,dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl,octadecyl, nonaclecyl, eicosyl, heneicosyl, docosyl, tricosyl,tetracosyl, pentacosyl, hexacosyl and beptacosyl radicals; R representsan alkyl group of from 4 to 27 carbon atoms; M represents ammoniumradical, an inorganic radical derived from an alkali metal compound,e.g., sodium carbonate, sodium hydroxide, potassium hydroxide, lithiumhydroxide, etc., or an organic compound of the alkali metal salt thereofsuch as N-methyltaurine, 'sodium-N-methylsarcosinate, sarcosine, sodiumsarcosinate, etc.; it is an integer representing the degree ofoxyethylation ranging from 1 to 40 moles of ethylene oxide per mole ofalkyl phenol;

w om-onion] O i -OM ill at and y represent positive integers rangingfrom i to 2, 2: being 1 when y is 2, and y being i when x is 2.

The salts utilized for purposes of the invention are prepared from knownphosphate esters of ethylene oxide addition products of alkyl phenols.Such acid esters can be readily prepared, for example, by este-rifyingan alkyl phenol such as nonyl phenol, dodecyl phenol, octadecyl phenol,dibutyl phenol or dinonyl phenol with phosp-orus pentoxide (P 0 undersubstantially anhydrous conditions at a temperature below about 115 C.for a period of four or more hours, as described in United StatesPatents 3,004,056 and 3,004,057.

The organic and inorganic salts may be formed in any known manner. Thepreferred method of preparation involves neutralizing the acid phosphatediester to a pH of about 7.0 to 7.5, followed by purification andrecovery of the salt.

The anti-static agents thus formed may be applied to the film in variousways to eliminate static. As an example, they may be applied asconstituents of the emul sion, as a constituent of a surface layer overthe emulsion or over the base, in which instance the layer might betermed as a noncurl layer. In other instances the anti-static agent maybe used as a constituent of a rinse solution applied to the surfaces ofthe film. A preferred procedure is to coat the film base with a gelatinsub-layer to which the anti-static agent has been added thereto in aconcentration ranging from 10 to 200 grams or more per kilogram of drygelatin.

The anti-static agents described may be used in various kinds ofphotographic emulsions. In addition to being useful in orthochrom-aticand panchromatic emulsions, they may also be used in non-sensitizedemulsions, X-ray emulsions, paper emulsions, color emulsions or thelike.

They may be used in combination with known antifoggants and stabilizers,reductionand metal-and noble metal sensitizers or in combination withother additive agents, and the like. The anti-static agents may also beemployed in gelatin carriers, or other colloids such as water-solublecellulose derivatives, e.g., hydroxy ethyl cellulose, methyl cellulose,low acetyl value cellulose acetate, and the like. Moreover, they may beincorporated on any conventional support for the emulsion such as acellulose organic ester, e.g., cellulose acetate, cellulose propionate,etc., or filmtorming polymers, such as polyvinyl chloride, copolymers ofvinyl chloride-vinyl acetate, and the like.

The following examples illustrate the best mode now contemplated forcarrying out the invention.

EXAMPLE 1 Light-sensitive silver halide photographic samples oi mm. highspeed X-ray film were surface coated individually with a 2% gelatinsolution containing (1) 20% by weight of sodium sarcosinatc, (2) 20% byweight of the acid phosphate ester formed from a polyoxyethylated nonylphenol (6 moles of ethylene oxide per mole of nonyl phenol) and (3) 20%by weight of the sodium sarcosinatc salt of the acid phosphate esterformed from a polyoxycthylated nonyl phenol (6 moles of ethylene oxideper mole of nonyl phenol). Each of the coatings also contained a typicalspreading agent and hardener finals. The films were conditioned at 22%and 42% humidities and tested for electrical conductance by standardelectrode technique. As shown in Table l, the antistatic agent of theinvention has a lower resistivity than the control by a factor of morethan 14 at a relative humidity of 22% and 42%.

Patented August 2, i060 1 No special surface additive.

EXAMPLE 2 The light-sensitive film samples prepared in Example 1 werealso given a practical handling test to determine finger rubsusceptibility. The finger rub tests were examined for static handlingmarks on eight pieces of each sample. As illustrated below in Table II,the control sample, the sodium sarcosinate and acid phosphate ester allshowed considerable static in most of the pieces. The anti-static agentof the invention, however, produced static-free samples.

Table II Sample i N i L M H 1 Control 2 3 3 (1) 1 7 0 0 (2) 0 2 2 4 (3)8 0 0 O 1 No special surface additive.

1 Number of strips having No, Light, Medium or Heavy static.

Various modifications of the invention will occur to persons skilled inthe art. Thus, it is evident that in lieu of using the compounds of theexamples, any of the compounds mentioned above can be employed withsimilar results. Therefore, it is not intended that the invention belimited in the patent granted except as necessitated by the appendedclaims.

O-(CHr-ClIzOh] O wherein R represents an alkyl group of from 4 to 27carbon atoms; R; is a member of the group consisting of hydrogen and analkyl group of from 4 to 27 carbon atoms; M represents a radical derivedfrom a salt-forming compound; n represents the degree of oxyethylationranging from 1 to x and y are positive integers ranging from 1 to 2, xbeing 2 when is 1 and y being 2 when x is l.

2. The material of claim 1 wherein the anti-static layer is located in alayer adjacent to the photographic emulsion layer.

3. The material of claim 2 wherein the anti-static layer is located ingelatin.

4. The material of claim 3 wherein the salt-forming compound is sodiumsarcosinate.

References Cited by the Examiner UNITED STATES PATENTS 2,639,234 5/1953Marcy et al. 96-87 3,004,056 10/1961 Nunn er al 252-351 3,039,870 6/1962Laakso et al 96--87 NORMAN G. TORCHIN, Primary Examiner.

T. I. HOFFMANN, Examiner.

R. H. SMITH, Assistant Examiner.

1. A PHOTOGRAPHIC MATERIAL COMPRISING A SUPPORT CARRYING A PHOTOGRAPHICSILVER HALIDE EMULSION LAYER AND AN ANTI-STATIC LAYER COMPRISING A SALTOF A PHOSPHATE ESTER HAVING THE FORMULA: